A vehicle behavior control device is known that stabilizes a vehicle posture while a vehicle is turning, and suppresses vehicle behavior disturbance due to oversteering or understeering. Further, a vehicle behavior control device may separately brake four wheels to stabilize a vehicle posture while turning when the vehicle posture is disturbed in a case of an abrupt steering operation due to a sudden change of road conditions or hazard avoidance.
The vehicle behavior control device controls, based on a yaw rate of the vehicle, a hydraulic pressure to pressurize one of wheel cylinders in a hydraulic pressure system including a pair of wheel cylinders and suppresses excessive oversteering or understeering, to stabilize the vehicle behavior while the vehicle is turning (for example, see Patent Document 1).
More specifically, when the vehicle behavior control device detects understeering while the vehicle is turning left without a brake pedal being operated, and, a pressure in a wheel cylinder in a rear inner wheel is increased and a pressure in a wheel cylinder in a diagonal (front outer) wheel from the rear inner wheel is reduced. On the other hand, when oversteering is detected, pressures in wheel cylinders in outer (both front and rear) wheels are increased and pressures in wheel cylinders in the diagonal wheels are reduced.
In addition, when the vehicle behavior control device detects understeering while the vehicle is turning left with the brake pedal being operated, the pressure in the wheel cylinder in the rear inner wheel is increased and the pressure in the wheel cylinder in the diagonal (front outer) wheel from the rear inner wheel is adjusted to a master pressure (pressure in a master cylinder). When oversteering is detected, the pressures in the wheel cylinders in the outer (both front and rear) wheels are increased and the pressures in the wheel cylinders in the diagonal wheels are adjusted to the master pressure.
This allows the vehicle behavior to be stabilized when the vehicle is turning left.